I'm no expert on JDO, but the low-level api does guarantee strong consistency for get-by-key operations (that is, unless you explicitly ask for eventual consistency). One of those SO responses suggested it is possible to have the GAE/JDO plugin log its low-level operations - that should at least point you in the right direction.
One other thing that might be related: In the low-level API, within a single transaction, all reads will return the original value even if you write it within the transaction. I don't know what JDO does with this; I would expect that subsequent reads would return a session-cached instance and hide this little quirk. But maybe it's related to what you are seeing? Jeff On Mon, Aug 3, 2015 at 1:52 PM, Thomas Becker <walkswiththeb...@gmail.com> wrote: > Thanks for your quick reply, Ryan. I have found several postings on the > Web that describe the same problem, namely, GetObjectById returning stale > data. Here are two from StackOverflow: > > > http://stackoverflow.com/questions/26377347/inconsistent-fetch-from-google-app-engine-datastore > > > http://stackoverflow.com/questions/22005349/appengine-jdo-with-multiple-server-instances-loses-transaction-updates-on-entiti > > Under the circumstances, I don't think it would be a good use of my time > to make a demo app. It seems clear to me that the issue exists. Besides, > the problem is so intermittent that a demo app is of very limited value. I > would be perfectly happy with a statement of the kind, "GetObjectById() > does not guarantee strong consistency, that's how it is, and here's what > you do instead to get strongly consistent data." I just need to know what's > going on. > > On Mon, Aug 3, 2015 at 2:32 PM, Ryan (Cloud Platform Support) < > rbruy...@google.com> wrote: > >> If you can create a sample app that shows this post on it on the PIT >> <https://code.google.com/p/googleappengine/issues/entry> so I can >> investigate this further. >> >> On Saturday, August 1, 2015 at 6:24:55 PM UTC-4, Thomas Becker wrote: >>> >>> I am using the app engine datastore with Java JDO. According to the >>> documentation, ancestor queries are always strongly consistent. Recently, >>> however, I've been seeing a lot of stale data from ancestor queries. It >>> seems to happen randomly. A query may return the most recent data, and a >>> moment later, the same query returns stale data. >>> >> -- >> You received this message because you are subscribed to a topic in the >> Google Groups "Google App Engine" group. >> To unsubscribe from this topic, visit >> https://groups.google.com/d/topic/google-appengine/1re1FtqllnQ/unsubscribe >> . >> To unsubscribe from this group and all its topics, send an email to >> google-appengine+unsubscr...@googlegroups.com. >> To post to this group, send email to google-appengine@googlegroups.com. >> Visit this group at http://groups.google.com/group/google-appengine. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/google-appengine/9723734e-0b14-49c0-8c31-3407df8454ad%40googlegroups.com >> <https://groups.google.com/d/msgid/google-appengine/9723734e-0b14-49c0-8c31-3407df8454ad%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> For more options, visit https://groups.google.com/d/optout. >> > > -- > You received this message because you are subscribed to the Google Groups > "Google App Engine" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to google-appengine+unsubscr...@googlegroups.com. > To post to this group, send email to google-appengine@googlegroups.com. > Visit this group at http://groups.google.com/group/google-appengine. > To view this discussion on the web visit > https://groups.google.com/d/msgid/google-appengine/CAPxj-GA3OKiGfjwgYgKmvZ%3DSi7ZXG3VLvts7%2BjWZ7c2CsC693Q%40mail.gmail.com > <https://groups.google.com/d/msgid/google-appengine/CAPxj-GA3OKiGfjwgYgKmvZ%3DSi7ZXG3VLvts7%2BjWZ7c2CsC693Q%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Google App Engine" group. To unsubscribe from this group and stop receiving emails from it, send an email to google-appengine+unsubscr...@googlegroups.com. To post to this group, send email to google-appengine@googlegroups.com. Visit this group at http://groups.google.com/group/google-appengine. To view this discussion on the web visit https://groups.google.com/d/msgid/google-appengine/CADK-0uh4Q8kswYMhD5RcxeQJnO3rFshgkfGEbB%2BXzHVXQLbGiw%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
